Resin molding, surface mounted light emitting apparatus and methods for manufacturing the same

ABSTRACT

The present invention provides a surface mounted light emitting apparatus which has long service life and favorable property for mass production, and a molding used in the surface mounted light emitting apparatus. The surface mounted light emitting apparatus comprises the light emitting device 10 based on GaN which emits blue light, the first resin molding 40 which integrally molds the first lead 20 whereon the light emitting device 10 is mounted and the second lead 30 which is electrically connected to the light emitting device 10, and the second resin molding 50 which contains YAG fluorescent material and covers the light emitting device 10. The first resin molding 40 has the recess 40c comprising the bottom surface 40a and the side surface 40b formed therein, and the second resin molding 50 is placed in the recess 40c. The first resin molding 40 is formed from a thermosetting resin such as epoxy resin by the transfer molding process, and the second resin molding 50 is formed from a thermosetting resin such as silicone resin.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of co-pending U.S. patent applicationSer. No. 15/896,856 filed on Feb. 14, 2018, which is a Continuation ofU.S. application Ser. No. 15/466,268 filed on Mar. 22, 2017, now U.S.Pat. No. 9,929,318 issued on Mar. 27, 2018, which is a Continuation ofU.S. application Ser. No. 13/828,118 filed Mar. 14, 2013, now U.S. Pat.No. 9,634,204 issued on Apr. 25, 2017, which is a Continuation of U.S.application Ser. No. 12/162,974 filed Sep. 23, 2008, now U.S. Pat. No.9,502,624 issued on Nov. 22, 2016, which is the National Phase of PCTInternational Application No. PCT/JP2006/309927 filed May 18, 2006. Theentire contents of all the above applications are hereby incorporated byreference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a surface mounted light emittingapparatus used in illumination apparatus, display, backlight for mobilephone, auxiliary light source for illumination or other light source forconsumer electric apparatus, a resin molding suitable for the surfacemounted light emitting apparatus and methods for manufacturing both.

Description of the Related Art

A surface mounted light emitting apparatus which employs a lightemitting device is compact, has high power efficiency and emits light ofclear color. The light emitting device is also free from burnout,because it is a semiconductor device. It also has an excellent initialdrive characteristic, and high durability against vibration andrepetitive cycles of turning on and off. Because of such excellentcharacteristics, light emitting apparatuses which use light emittingdevices such as light emitting diode (LED) or laser diode (LD) are usedas various light sources.

FIG. 11 shows a surface mounted light emitting apparatus of the priorart. The surface mounted light emitting apparatus of the prior artcomprises a light emitting device 210, a lead frame for mounting 220 formounting the former thereon, a lead frame for connection 230 which isconnected to the light emitting device 210 via leads, and a molding 240which covers most of the lead frames (refer to, for example, JapaneseUnexamined Patent Publication (Kokai) No. 11-087780 (claims, paragraph[0020])). In the surface mounted light emitting apparatus, the molding240 is often formed from a light blocking resin such as liquid crystalpolymer, PPS (polyphenyl sulfide) or nylon which is a thermoplasticresin for the reason of convenience in mass production. Also because thethermoplastic resin used in the molding 240 is required to have enoughheat resistance to endure the heat of reflow soldering, engineeringpolymers such as polyphthalamide, liquid crystal polymer and PPS areused. The thermoplastic resin is formed by injection molding process.The injection molding process is employed in preference for the reasonof high productivity thereof, in the manufacture of the surface mountedlight emitting apparatus which has high output power at a low cost.

The thermoplastic engineering plastics as mentioned above used informing the molding 240 for the surface mounted light emitting apparatusof the prior art have high heat resistance, although contains anaromatic component in the molecule and therefore have low resistance tolight. Also because these materials do not have hydroxide group whichimproves adhesive property at the end of the molecule, sufficientbonding cannot be achieved between the lead frames 220, 230 and thetranslucent encapsulant resin 250. Moreover, as the light emittingdevices are produced with rapidly increasing output power in recentyears, the problem of light degradation of the molding 240 is becomingmore conspicuous. Bonding between the translucent encapsulant resin 250and the thermoplastic engineering polymer 240, in particular, can beeasily destroyed due in part to the weak bonding strength, thusresulting in delamination. Even when the delamination does not result,discoloration caused by light degradation proceeds and results indrastically short life of the light emitting device.

There is a technology proposed to solve these problems which forms themolding from an inorganic material that is free from light degradation,such as ceramics. However, the molding formed from ceramics makes itdifficult to insert the lead frame which has high thermal conductivity,and therefore resistance to heat transfer cannot be decreased. Alsobecause the thermal expansion coefficient is different from that of thetranslucent encapsulant resin by a factor of 10 or more, sufficientlevel of reliability has not been achieved.

SUMMARY OF THE INVENTION

With the background described above, an object of the present inventionis to provide a surface mounted light emitting apparatus which has longservice life and is suitable for mass production, and a molding used tomake the surface mounted light emitting apparatus. Another object is toprovide a method for easily manufacturing the surface mounted lightemitting apparatus and the molding.

Through research for solving the problems described above, the inventorof the present application completed the invention.

The present invention is a surface mounted light emitting apparatuscomprising a light emitting device, a first resin molding whichintegrally molds a first lead whereon the light emitting device isplaced and a second lead electrically connected to the light emittingdevice, and a second resin molding which covers the light emittingdevice, wherein the first resin molding has a recess comprising a bottomsurface and a side surface, the first lead is exposed on the bottomsurface of the recess of the first resin molding, the light emittingdevice is mounted on the exposed portion, and the first resin moldingand the second resin molding are formed from thermosetting resins. Thethermosetting resins are preferably such that do not have aromaticcomponent in the molecule, if possible.

The present invention is a surface mounted light emitting apparatuscomprising a light emitting device, a first resin molding whichintegrally molds a first lead whereon the light emitting device ismounted and a second lead electrically connected to the light emittingdevice, and a second resin molding which covers the light emittingdevice, wherein the first lead has a first inner lead and a first outerlead with the first inner lead having the light emitting device mountedthereon and electrically connected to a first electrode of the lightemitting device and the first outer lead is exposed from the first resinmolding, while the second lead has a second inner lead and a secondouter lead with the second inner lead being electrically connected to asecond electrode of the light emitting device, the second outer lead isexposed from the first resin molding, the first resin molding has arecess comprising a bottom surface and a side surface, the first innerlead is exposed from the bottom surface of the recess of the first resinmolding, the light emitting device is mounted on the exposed portion,and the first resin molding and the second resin molding are formed fromthermosetting resin. The thermosetting resin is preferably such thatdoes not have aromatic component in the molecule, if possible.

The back side of the first lead, opposite to the principal surface wherethe light emitting device is placed, is preferably exposed from thefirst resin molding.

The back sides of the first lead and the second lead, opposite to theprincipal surface where the light emitting device is placed, may beexposed from the first resin molding.

The exposed portion of the back side of the first lead and the exposedportion of the back side of the second lead preferably lie onsubstantially the same plane.

The exposed portion of the back side of the first inner lead may beplaced in such a manner as a heat sink makes contact therewith.

The first resin molding is formed by transfer molding process.

The first resin molding is preferably formed from at least one kindselected from among the group consisting of epoxy resin, modified epoxyresin, silicone resin, modified silicone resin, acrylate resin andurethane resin.

The first resin molding may contain at least one kind selected fromamong the group consisting of filler, diffusing agent, pigment,fluorescent material, reflective material and light blocking material.

The second resin molding may contain at least one kind selected fromamong the group consisting of filler, diffusing agent, pigment,fluorescent material and reflective material.

The present invention is a resin molding which integrally molds a firstlead a second lead, wherein the first lead has a first inner lead and afirst outer lead with the first inner lead placed in the resin moldingand the first outer lead being exposed from the resin molding, thesecond lead has a second inner lead and a second outer lead with thesecond inner lead being placed in the resin molding and the second outerlead being exposed from the resin molding, while the resin molding has arecess comprising a bottom surface and a side surface, the first innerlead and the second inner lead are exposed from the bottom surface ofthe recess of the resin molding, and the resin molding is formed from athermosetting resin.

The present invention is a resin molding which integrally molds a firstlead a second lead, wherein the first lead has a first inner lead and afirst outer lead with the first inner lead being placed in the resinmolding and the first outer lead being exposed from the resin molding,the second lead has a second inner lead and a second outer lead with thesecond inner lead being placed in the resin molding and the second outerlead being exposed from the resin molding, while the resin molding has arecess comprising a bottom surface and a side surface, the first innerlead and the second inner lead are exposed from the bottom surface ofthe recess of the resin molding, the back side of the first inner leadwhich is opposite to the principal surface where the recess is formed isexposed from the resin molding, and the resin molding is formed from athermosetting resin.

The exposed portion of the back side of the first lead and the exposedportion of the back side of the second lead preferably lie onsubstantially the same plane.

The thermosetting resin is preferably at least one kind selected fromamong the group consisting of epoxy resin, modified epoxy resin,silicone resin, modified silicone resin, acrylate resin and urethaneresin.

The resin molding is formed by the transfer molding process.

The resin molding may contain at least one kind selected from among thegroup consisting of filler, diffusing agent, pigment, fluorescentmaterial, reflective material and light blocking material mixed therein.

The present invention is a method of manufacturing the resin moldingwhich integrally molds the first lead the second lead and has the recesscomprising the bottom surface and the side surface, wherein an upper diehas a recess corresponding to the recess of the resin molding, the firstlead has the first inner lead and the first outer lead, the second leadhas the second inner lead and the second outer lead, the methodcomprising a first process where the first inner lead and the secondinner lead corresponding to the bottom of the recess of the resinmolding and the first outer lead and the second outer lead areinterposed between the upper die and a lower die, a second process wherethe thermosetting resin is poured into the cavity formed between theupper die and the lower die by the transfer molding process, and a thirdprocess where the thermosetting resin poured into the cavity is heatedso as to be cured and form the resin molding.

The present invention is a method of manufacturing the surface mountedlight emitting apparatus which comprises the resin molding that moldsintegrally the first lead the second lead and has the recess comprisingthe bottom surface and the side face, the light emitting device placedon the first lead and the second resin molding which covers the lightemitting device, wherein the upper die has a recess corresponding to therecess of the resin molding, the first lead has the first inner lead andthe first outer lead, the second lead has the second inner lead and thesecond outer lead, the method comprising a first process where the firstinner lead and the second inner lead corresponding to the bottom surfaceof the recess of the first resin molding and the first outer lead andthe second outer lead are interposed between the upper die and the lowerdie, a second process where the first thermosetting resin is poured intothe cavity formed between the upper die and the lower die by thetransfer molding process, a third process where the first thermosettingresin that is poured into the cavity is heated so as to be cured, afourth process where the upper die is removed, a fifth process where thelight emitting device is mounted on the first inner lead with the firstelectrode of the light emitting device and the first inner lead beingelectrically connected with each other and the second electrode of thelight emitting device and the second inner lead being electricallyconnected with each other, a sixth process where a second thermosettingresin is placed in the recess where the light emitting device ismounted, and a seventh process where the second thermosetting resin isheated so as to be cured and form the second resin molding.

The present invention, constituted as described above, has the effectsdescribed below.

The present invention is a surface mounted light emitting apparatuscomprising the light emitting device, the first resin molding whichintegrally molds the first lead whereon the light emitting device ismounted and the second lead which is electrically connected to the lightemitting device and the second resin molding which covers the lightemitting device, wherein the first resin molding has a recess comprisinga bottom surface and a side surface, the first lead is exposed from thebottom surface of the recess of the first resin molding, the lightemitting device is mounted on the exposed portion, and the first resinmolding and the second resin molding are formed from thermosettingresins.

This constitution makes it possible to provide the surface mounted lightemitting apparatus which has heat resistance and high resistance tolight.

By forming the first resin molding from the thermosetting resin, it ismade possible to prevent delamination from occurring in the interfacewith the second resin molding. This is because the thermosetting resinhas a number of reactive functional groups on the surface thereof and istherefore capable of forming an interface for firm bonding with thesecond resin molding, unlike a thermoplastic resin. Also by forming thesecond resin molding from a thermosetting resin, it is made possible toachieve isotropic thermal expansion and shrinkage behavior similar tothat of the first resin molding, and therefore thermal stress in theinterface of bonding due to temperature change can be decreased further.In addition, by forming the second resin molding from the thermosettingresin similar to that of the first resin molding, it is made possiblenot only to achieve the improvement of the bonding strength throughreduction of the surface tension, but also to achieve very strongbonding due to the progress of curing reaction in the interface. As forthe light resistance, the aromatic component which has low lightresistance can be easily removed because the composition of thethermosetting resin which has 3-dimensional cross linkage structure canbe easily changed without compromising the heat resistance. In the caseof a thermoplastic resin, heat resistance and an aromatic component arevirtually synonym, and a molding which can endure the heat of reflowsoldering cannot be obtained without containing an aromatic component.Therefore, by forming the first resin molding and the second resinmolding from the thermosetting resin, it is made possible to make thesurface mounted light emitting apparatus which has inherently stronginterface of bonding, high resistance to delamination and undergoingless light degradation with less aging effect.

The second resin molding is placed in the recess where the lightemitting device is mounted. This constitution enables it to easily coverthe light emitting device. Also because the light emitting device has arefraction index significantly different from that of air, light emittedby the light emitting device does not emerge efficiently to the outside,while covering the light emitting device with the second resin moldingallows the light emitted by the light emitting device to emergeefficiently to the outside. Also light emitted by the light emittingdevice is reflected on the bottom surface and the side surface of therecess, and emerges from the principal surface side where the lightemitting device is mounted. Thus the optical output from the principalsurface can be improved. As a result, light emitted by the lightemitting device can be reflected with higher efficiency since the firstlead is made of a metal, than in the case where the bottom surface ofthe recess is covered by the first resin molding.

For example, epoxy resin may be used for the first resin molding andhard silicone resin may be used for the second resin molding.

The present invention is the surface mounted light emitting apparatuscomprising the light emitting device, the first resin molding whichintegrally molds the first lead whereon the light emitting device isplaced and the second lead which is electrically connected to the lightemitting device, and the second resin molding which covers the lightemitting device, wherein the first lead has the first inner lead and thefirst outer lead with the first inner lead having the light emittingdevice placed thereon and is electrically connected to the firstelectrode of the light emitting device and the first outer lead isexposed from the first resin molding, the second lead has the secondinner lead and the second outer lead with the second inner lead beingelectrically connected to the second electrode of the light emittingdevice and exposed from the first resin molding, the first resin moldinghas the recess comprising the bottom surface and the side face, thefirst inner lead is exposed on the bottom surface of the recess of thefirst resin molding, the light emitting device is placed on the exposedportion, and the first resin molding and the second resin molding areformed from thermosetting resin. With this constitution, the surfacemounted light emitting apparatus which is excellent in heat resistance,light resistance and in bonding strength can be made. Also because thefirst resin molding and the second resin molding are formed from thethermosetting resin, the first resin molding and the second resinmolding can be prevented from peeling off each other. Moreover, sincethe first lead and the second lead of predetermined lengths are used bybending or otherwise processing, electrical connection with the externalelectrode can be easily established and the device can be used simply bymounting on an existing illuminating apparatus.

The back side of the first lead, opposite to the principal surface wherethe light emitting device is mounted, is preferably exposed from thefirst resin molding. When electric power is supplied to the surfacemounted light emitting apparatus, the light emitting device emits lightand, at the same time, generates heat. The constitution described aboveenables it to efficiently dissipate the heat to the outside. Especiallybecause the heat generated by the light emitting device can betransferred to the outside in the shortest path possible, very efficientheat dissipation is achieved.

The back sides of the first lead and of the second lead, opposite to theprincipal surface where the light emitting device is mounted, may beexposed from the first resin molding. This constitution enables it toefficiently dissipate the heat generated by the light emitting device tothe outside. The first lead and the second lead function as electrodes,and therefore can be very easily connected to external terminals.Especially when the first lead and the second lead having largethickness are used, this constitution makes mounting easier even whenthese leads are difficult to bend. Also because the first lead and thesecond lead are held between predetermined dies in the manufacturingprocess, occurrence of burrs can be reduced and mass productivity can beimproved. However, whole surface of the back sides of the first lead andof the second lead may not be exposed, and only the portion where it isdesired to suppress the occurrence of burrs may be exposed.

The exposed portion of the back side of the first lead and the exposedportion of the back side of the second lead preferably lie substantiallyin the same plane. This enables it to improve the stability duringmounting of the surface mounted light emitting apparatus. Also becausethe exposed portions lie in the same plane, the surface mounted lightemitting apparatus may be mounted on an external electrode of flat plateshape by means of a solder, which enables it to improve the ease ofmounting the surface mounted light emitting apparatus. In addition, itmakes it very easy to mold by means of dies.

The exposed portion of the back side of the first inner lead may bedisposed so as to make contact with the heat sink. In addition to thearrangement of the heat sink as an external member separately from thesurface mounted light emitting apparatus, the heat sink may also bedisposed integrally with the surface mounted light emitting apparatus.With this configuration, since heat generated by the light emittingdevice is dissipated through the heat sink to the outside, the heatdissipation performance can be improved further. Also in case the heatsink is disposed as an external member, the position where the surfacemounted light emitting apparatus is mounted can be easily determined.

The first resin molding is formed by the transfer molding process. Whilecomplex shapes cannot be formed by the injection molding process, thetransfer molding process is capable of forming complex shapes. The firstresin molding which has the recess, in particular, can be formed easily.

The first resin molding is preferably formed from at least one kindselected from among the group consisting of epoxy resin, modified epoxyresin, silicone resin, modified silicone resin, acrylate resin andurethane resin. Among these, epoxy resin, modified epoxy resin, siliconeresin and modified silicone resin are preferably used and epoxy resin isparticularly preferable. Use of such a material makes it possible toprovide the surface mounted light emitting apparatus having high heatresistance, high light resistance, high bonding strength and ease ofmanufacturing in mass production. The first resin molding can besuppressed from degrading by using a thermosetting resin in forming thefirst resin molding than using a thermoplastic resin, thus elongatingthe service life of the surface mounted light emitting apparatus.

The first resin molding may contain at least one kind selected fromamong the group consisting of filler, diffusing agent, pigment,fluorescent material, reflective material and light blocking materialmixed therein. Various materials are added in accordance to therequirement of the first resin molding. For example, a resin having hightranslucency may be used in the first resin molding and a fluorescentmaterial may be mixed in the first resin molding. With thisconstitution, light emerging through the side face or the bottom surfaceof the light emitting device is absorbed by the fluorescent material andis emitted after being subjected to wavelength conversion, so that lightof the desired color can be obtained from the surface mounted lightemitting apparatus as a whole. For example, in order to diffuse theemitted light uniformly, filler, diffusing agent, reflective material orthe like may be added to the side face or the bottom of the lightemitting device. For example, in order to reduce the light emerging fromthe back surface of the surface mounted light emitting apparatus, atranslucent resin may be mixed. Particularly, it is preferable that thefirst resin molding is formed from epoxy resin which contains titaniumoxide and silica or alumina mixed therein, which enables it to providethe surface mounted light emitting apparatus having high heatresistance.

The second resin molding may contain at least one kind selected fromamong the group consisting of filler, diffusing agent, pigment,fluorescent material and reflective material mixed therein. Variousmaterials are added in accordance to the requirement of the second resinmolding. For example, a fluorescent material may be mixed in the secondresin molding so as to achieve a color of light different from that ofthe light emitted by the light emitting device. White light can beproduced by, for example, using a light emitting device which emits bluelight and a fluorescent material which emits yellow light. In order toemit uniformly, filler and/or diffusing agent may also be mixed.

The present invention is a resin molding which integrally molds thefirst lead and the second lead, wherein the first lead has the firstinner lead and the first outer lead with the first inner lead beingplaced in the resin molding and the first outer lead being exposed fromthe resin molding, the second lead has the second inner lead and thesecond outer lead with the second inner lead being placed in the resinmolding and the second outer lead being exposed from the resin molding,while the resin molding has the recess comprising the bottom surface andthe side face, the first inner lead and the second inner lead areexposed from the bottom surface of the recess of the resin molding, andthe resin molding is formed from a thermosetting resin. Thisconstitution makes it possible to provide better resin molding havinghigher heat resistance, higher light resistance and higher bondingstrength than in the case of forming the resin molding from athermoplastic resin. It is also made possible to make the structurewhere the light emitting device can be easily placed.

The present invention is a resin molding which integrally molds thefirst lead and the second lead, wherein the first lead has the firstinner lead and the first outer lead with the first inner lead beingplaced in the resin molding and the first outer lead being exposed fromthe resin molding, the second lead has the second inner lead and thesecond outer lead with the second inner lead being placed in the resinmolding and the second outer lead being exposed from the resin molding,while the resin molding has the recess comprising the bottom surface andthe side surface, the first inner lead and the second inner lead areexposed from the bottom surface of the recess of the resin molding, theback side of the first inner lead which is opposite to the principalsurface where the recess is formed is exposed from the resin molding,and the resin molding is formed from a thermosetting resin. Thisconstitution makes it possible to provide the resin molding havinghigher heat resistance, higher light resistance and higher bondingstrength than in the case of forming the resin molding from athermoplastic resin. It is also made possible to make the structurewhere the light emitting device can be easily placed. Also by exposingthe first outer lead which extends from the resin molding, heatgenerated from the light emitting device can be dissipated to theoutside.

The exposed portion of the back side of the first lead and the exposedportion of the back side of the second lead preferably lie onsubstantially the same plane. This makes it possible to provide thesurface mounted light emitting apparatus which uses the resin moldingthat has satisfactory stability and is easy to mount. It is also easy tomold by means of dies.

The thermosetting resin is preferably at least one kind selected fromamong the group consisting of epoxy resin, modified epoxy resin,silicone resin, modified silicone resin, acrylate resin and urethaneresin. These materials enable it to provide the rein molding which hasfavorable property for mass production, higher heat resistance andhigher light resistance at a low cost.

The resin molding is formed by the transfer molding process which iscapable of forming recesses of complex shapes that are difficult to formby the injection molding process.

The resin molding may contain at least one kind selected from among thegroup consisting of filler, diffusing agent, pigment, fluorescentmaterial, reflective material and light blocking material. Suchadditives enable it to provide the resin molding which satisfiesspecific requirements. For example, in case the resin molding which haslight diffusion effect is desired, a filler and/or a diffusing agent aremixed. In case the surface mounted light emitting apparatus whichconverts the wavelength of light and emits light of a desired color isrequired, fluorescent material is mixed. In case it is desired to blockthe transmission of light to the back surface in order to efficientlyextract light emitted by the light emitting device on the principalsurface side, light blocking material is mixed.

The present invention is a method for manufacturing the resin moldingwhich integrally molds the first lead and the second lead and has therecess comprising the bottom surface and the side face formed therein,wherein an upper die has a recess corresponding to the recess of theresin molding, the first lead has the first inner lead and the firstouter lead, the second lead has the second inner lead and the secondouter lead, the method comprising a first process where the first innerlead and the second inner lead corresponding to the bottom surface ofthe recess of the resin molding and the first outer lead and the secondouter lead are interposed between the upper die and the lower die, asecond process where the thermosetting resin is poured into the cavityformed between the upper die and the lower die by the transfer moldingprocess, and a third process where the thermosetting resin which hasbeen poured into the cavity is heated so as to be cured and form theresin molding.

With this method, since the first inner lead and the second inner leadare interposed between the upper die and the lower die in the firstprocess, these leads can be suppressed from fluttering during thetransfer molding process, so that the resin molding without burrs can bemade. It is also made possible to expose the first inner lead whichcorresponds to the portion whereon the light emitting device is mounted.Moreover, since the principal surface side and the back side of thefirst inner lead corresponding to the bottom surface of the recess areexposed, heat can be dissipated from the back side when the lightemitting device is mounted, thus improving the heat dissipationperformance.

Also the resin molding which has the recess of complex shape can be madesince it is formed from the thermosetting resin by the transfer moldingprocess. The resin molding which has favorable property for massproduction, higher heat resistance, higher light resistance and higherbonding strength can also be made. The thermosetting resin is onceheated to the melting temperature, and is then cooled to solidify. Thusthe thermoplastic resin and the thermosetting resin are subjected todifferent cooling processes, and are also different as to whether theycan be cured reversibly. The thermoplastic resin has high viscosityduring processing, and therefore cannot be formed into a complicatedshape by molding.

The present invention is a method for manufacturing the surface mountedlight emitting apparatus which comprises the first resin molding thatintegrally molds the first lead and the second lead and has the recesscomprising the bottom surface and the side surface, the light emittingdevice mounted on the first lead and the second resin molding whichcovers the light emitting device, wherein the upper die has the recesscorresponding to the recess of the first resin molding, the first leadhas a first inner lead and the first outer lead, the second lead has thesecond inner lead and the second outer lead, the method comprising thefirst process where the first inner lead and the second inner leadcorresponding to the bottom surface of the recess of the first resinmolding and the first outer lead and the second outer lead areinterposed between the upper die and the lower die, the second processwhere the first thermosetting resin is poured into the cavity formedbetween the upper die and the lower die by the transfer molding process,the third process where the first thermosetting resin which has beenpoured into the cavity is heated so as to be cured and form the firstresin molding, the fourth process where the upper die is removed, thefifth process where the light emitting device is placed on the firstinner lead with the first electrode of the light emitting device and thefirst inner lead being electrically connected with each other and thesecond electrode of the light emitting device and the second inner leadbeing electrically connected with each other, the sixth process wherethe second thermosetting resin is placed in the recess where the lightemitting device is mounted, and the seventh process where the secondthermosetting resin is heated so as to be cured and form the secondresin molding. This method enables it to manufacture the surface mountedlight emitting apparatus which has favorable property for massproduction. Also because the first resin molding and the second moldingare formed from the thermosetting resin, bonding strength between thefirst resin molding and the second molding can be made higher than inthe case of using a thermoplastic resin and a thermosetting resin. Whenthe first resin molding is formed by the transfer molding process, theleads are securely interposed by the upper die and the lower die so thatburrs are not formed despite the high fluidity of the resin often causethe problem of burrs. Since the leads which are interposed are exposed,the light emitting device can be placed on the exposed portion or theelectrodes of the light emitting device can be connected to the leads bywires.

The thermosetting resin, the first thermosetting resin and the secondthermosetting resin are preferably at least one kind selected from amongthe group consisting of epoxy resin, modified epoxy resin, siliconeresin, modified silicone resin, acrylate resin and urethane resin. Thisconstitution enables it to manufacture the surface mounted lightemitting apparatus which has favorable property for mass production.Also because these materials have high fluidity and can be easily heatedand cured, the surface mounted light emitting apparatus having high heatresistance and high light resistance can be manufactured withsatisfactory molding quality.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic sectional view showing the surface mounted lightemitting apparatus according to the first embodiment.

FIG. 2 is a schematic plan view showing the surface mounted lightemitting apparatus according to the first embodiment.

FIG. 3 is a schematic sectional view showing the state of mounting thesurface mounted light emitting apparatus according to the firstembodiment.

FIG. 4 is a schematic plan view showing the surface mounted lightemitting apparatus according to the second embodiment.

FIG. 5 is a schematic sectional view showing the surface mounted lightemitting apparatus according to the third embodiment.

FIG. 6 is a schematic sectional view showing the surface mounted lightemitting apparatus according to the fourth embodiment.

FIG. 7 is a schematic sectional view showing the surface mounted lightemitting apparatus according to the fifth embodiment.

FIG. 8 is a schematic sectional view showing the state of mounting thesurface mounted light emitting apparatus according to the thirdembodiment.

FIG. 9 is a schematic sectional view showing the surface mounted lightemitting apparatus according to the sixth embodiment.

FIGS. 10(a) through 10(e) are schematic sectional views showing theprocesses of manufacturing the surface mounted light emitting apparatusof the first embodiment.

FIG. 11 is a schematic plan view showing the surface mounted lightemitting apparatus of the prior art.

FIG. 12 is a schematic section view showing the surface mounted lightemitting apparatus of the prior art.

DESCRIPTION OF REFERENCE NUMERALS

-   10 light emitting device-   11 first electrode-   12 second electrode-   20 first lead-   20 a first inner lead-   20 b first outer lead-   30 second lead-   30 a second inner lead-   30 b second outer lead-   40 first resin molding-   40 a bottom surface-   40 b side surface-   40 c recess-   50 second resin molding-   60 wire-   70 filler-   80 fluorescent material-   90 insulating member-   100 heat dissipating adhesive-   110 heat sink-   120 upper die-   121 lower die-   210 light emitting device-   220 lead frame for mounting-   230 lead frame for connection-   240 molding-   250 translucent encapsulant resin

DETAILED DESCRIPTION OF THE INVENTION

The surface mounted light emitting apparatus and the resin molding ofthe present invention and the methods for manufacturing the same willnow be described by way of embodiments and Examples. However, thepresent invention is not limited to these embodiments and Examples.

First Embodiment

<Surface Mounted Light Emitting Apparatus>

The surface mounted light emitting apparatus according to the firstembodiment will be described with reference to the accompanyingdrawings. FIG. 1 is a schematic sectional view showing the surfacemounted light emitting apparatus according to the first embodiment. FIG.2 is a schematic plan view showing the surface mounted light emittingapparatus according to the first embodiment. FIG. 1 is a schematicsectional view along line I-I of FIG. 2.

The surface mounted light emitting apparatus according to the firstembodiment comprises a light emitting device 10, a first resin molding40 whereon the light emitting device 10 is mounted and the second resinmolding 50 which covers the light emitting device 10. The first resinmolding 40 integrally molds the first lead 20 whereon the light emittingdevice 10 is mounted and the second lead 30 which is electricallyconnected to the light emitting device 10.

The light emitting device 10 has a pair of positive and negativeelectrodes, a first electrode 11 and a second electrode 12, provided onthe same side. While a case of providing the pair of positive andnegative electrodes on the same side is described in this specification,the present invention may also be applied to a case where a pair ofpositive and negative electrodes are provided on the top surface and thebottom surface of the light emitting device. In this case, the electrodeprovided on the bottom surface of the light emitting device iselectrically connected to the first lead 20 by means of an electricallyconductive die bonding member, without using a wire.

The first lead 20 has a first inner lead 20 a and a first outer lead 20b. The light emitting device 10 is mounted on the first inner lead 20 avia the die bonding member. The first inner lead 20 a is electricallyconnected to the first electrode 11 of the light emitting device 10 viaa wire 60. The first outer lead 20 b is exposed from the first resinmolding 40. While the first lead 20 has the first outer lead 20 bprovided on the outside of the side face of the first resin molding 40,the portion exposed on the back of the first resin molding 40 may alsobe called the first outer lead 20 b, and the first outer lead 20 b maybe a portion which is electrically connected to the external electrode.The first lead 20 is formed from a metal so as to connect to theexternal electrode.

The second lead 30 has a second inner lead 30 a and a second outer lead30 b. The second inner lead 30 a is electrically connected to the secondelectrode 12 of the light emitting device 10 via the wire 60. The secondouter lead 30 b is exposed from the first resin molding 40. While thesecond lead 30 has the second outer lead 30 b provided on the outside ofthe side face of the second resin molding 40, the portion exposed on theback of the second resin molding 40 may also be called the second outerlead 30 b, and the second outer lead 30 b may be a portion which iselectrically connected to the external electrode. The second lead 30 isformed from a metal so as to connect to the external electrode. Aninsulation member 90 is provided in a portion where the first lead 20and the second lead 30 are located near to each other on the back side,in order to prevent the first lead 20 and the second lead 30 from shortcircuiting.

The first resin molding 40 has the recess 40 c which has the bottomsurface 40 a and the side surface 40 b. The first inner lead 20 a of thefirst lead 20 is exposed from the bottom surface 40 a of the recess 40 cof the first resin molding 40. The light emitting device 10 is mountedon the exposed portion via the die bonding member. The first resinmolding 40 is formed by transfer molding process. The first resinmolding 40 is formed from a thermosetting resin. It is preferable thatthe opening of the recess 40 c is made wider than the bottom 40 a, andthe side face 40 b is inclined.

The second resin molding 50 is placed in the recess 40 c so as to coverthe light emitting device 10. The second resin molding 50 is formed froma thermosetting resin. The second resin molding 50 contains afluorescent material 80. The fluorescent material 80 has a specificgravity higher than that of the second resin molding 50, and thereforeprecipitates on the bottom 40 a of the recess 40 c.

In this specification, the side where the light emitting device 10 ismounted is called the principal surface side, and the opposite side iscalled the back side.

The first resin molding 40 and the second resin molding 50 are formedfrom thermosetting resins and have physical properties which areproximate to each other, and therefore can bond with each other verywell. The constitution described above enables it to provide the surfacemounted light emitting apparatus having high heat resistance and highlight resistance.

Constituent components will now be described below.

<Light Emitting Device>

The light emitting device 10 is made by forming a light emitting layerfrom a semiconductor such as GaAlN, ZnS, ZnSe, SiC, GaP, GaAlAs, AlN,InN, AllnGaP, InGaN, GaN or AllnGaN on a substrate. The structure of thesemiconductor may be homo-junction structure, hetero junction structureor double hetero-junction structure having MIS junction, PIN junction orPN junction. Wavelength range of the emitted light can be selected froma wide region ranging from ultraviolet to infrared, by selecting thecomponents of the semiconductor layer and the mixing proportion thereof.The light emitting layer may be formed in a thin film which allowsquantum effect to appear, having either single quantum well structure ormultiple quantum well structure.

In consideration of outdoor use, it is preferable to use a galliumnitride-based compound semiconductor which enables it to form a lightemitting device of high brightness. To obtain the emission of red light,it is preferable to use a semiconductor based on gallium, aluminum orarsenic, or a semiconductor based on aluminum, indium, gallium orphosphorus, although various other semiconductors may also be useddepending on the application.

In case a gallium nitride-based compound semiconductor is used,sapphire, spinel, SiC, Si, ZnO or GaN single crystal or the like is usedfor the semiconductor substrate. Sapphire substrate is preferably usedin order to form gallium nitride which has favorable property for massproduction and high crystallinity. An example of the light emittingdevice 10 made by using nitride-based compound semiconductor is shown. Abuffer layer is formed from GaN, AlN or the like on a sapphiresubstrate. A first contact layer of P or N type GaN, an active layerconsisting of thin film of InGaN having quantum effect, a cladding layerof P or N type AlGaN and a second contact layer of P or N type GaN maybe formed in this order on the buffer layer. The gallium nitride-basedcompound semiconductor shows N type conductivity when it is not dopedwith an impurity. In order to form an N type gallium nitridesemiconductor of a desired property such as improved light emissionefficiency, it is preferable to add Si, Ge, Se, Te, C or the like as Ntype dopant.

In order to form a P type gallium nitride semiconductor, Zn, Mg, Be, Ca,Sr, Ba or the like is added as P type dopant. Since gallium nitridesemiconductor is difficult to turn into P type semiconductor simply bydoping with P type dopant, it is necessary to anneal by heating in afurnace, irradiating with low electron beam or irradiating with plasmaafter introducing a P type dopant. A semiconductor wafer made in thisway is subjected to partial etching and/or other process so as to formpositive and negative electrodes. Then the semiconductor wafer is cutinto desired size thereby making the light emitting devices.

The light emitting device 10 may be used in plurality, so as to achieveimproved color blending performance according to the combination in thedisplay of white color. For example, two light emitting devices 10 whichare capable of emitting green light and one light emitting device 10which is capable of emitting blue light and one light emitting device 10which is capable of emitting red light may be combined. For anapplication to a full-color display apparatus, it is preferable to havesuch a constitution that emits red light in a range of wavelengths from610 nm to 700 nm, green light in a range of wavelengths from 495 nm to565 nm and blue light in a range of wavelengths from 430 nm to 490 nm.In order to produce blended light of whitish color with the surfacemounted light emitting apparatus of the present invention, it ispreferable to have the light emitting device emit light in a range ofwavelengths not shorter than 400 nm and not longer than 530 nm and morepreferably not shorter than 420 nm and not longer than 490 nm, inconsideration of the complementary color relation with the light emittedby the fluorescent material and degradation of the translucent resin. Inorder to improve the efficiency of excitation and emission by the lightemitting device and the fluorescent material, the range of wavelengthsis more preferably not shorter than 450 nm and not longer than 475 nm. Alight emitting device which has principal wavelength of emission inultraviolet region shorter than 400 nm or in a short wavelength regionof visible light may be used in combination with a member which is lesssusceptible to degradation by ultraviolet rays.

The light emitting device 10 having size of 1 mm square can be mounted,and those having size of 600 μm square or 320 μm square can also bemounted.

<First Resin Molding>

The first resin molding 40 has the recess 40 c comprising the bottomsurface 40 a and the side face 40 b. The first resin molding 40integrally molds the first lead 20 which extends from the bottom surfacea of the recess 40 c and the second lead 30. The first inner lead 20 aof the first lead 20 forms a part of the bottom surface 40 a of therecess 40 c. The second inner lead 30 a of the second lead 30 forms apart of the bottom surface 40 a of the recess 40 c, and is disposed at apredetermined distance from the first inner lead 20 a. The lightemitting device 10 is mounted on the first inner lead 20 a whichcorresponds to the bottom surface 40 a of the recess 40 c. The firstinner lead 20 a which corresponds to the bottom surface 40 a of therecess 40 c, the second inner lead 30 a which corresponds to the bottomsurface 40 a of the recess 40 c, the first outer lead 20 b and thesecond outer lead 30 b are exposed from the first resin molding 40. Thefirst lead 20 and the second lead 30 on the back side are exposed. Thisconstitution enables it to establish electrical connection from the backside.

The recess 40 c is formed with inclined surface so as to become widertoward the mouth. This configuration improves the efficiency ofextracting light in the front direction. The recess 40 c may be,however, formed in a tubular shape instead of being inclined. Theinclined surface is preferably smooth, although may be roughened. Roughsurface makes it possible to improve the bonding between the first resinmolding 40 and the second resin molding 50. Angle of inclination of therecess 40 c from the bottom surface is preferably from 95 to 105degrees, more preferably from 100 to 120 degrees.

Shape of the first resin molding 40 on the principal surface side isrectangular, although it may also be oval, circle, pentagon, hexagon orother shape. Shape of the recess 40 c on the principal surface side isoval, although it may also be substantially circular, rectangular,pentagon, hexagon or other shape. A cathode mark may be attached asrequired.

The material of the first resin molding 40 is a thermosetting resin. Thefirst resin molding is preferably formed of at least one kind selectedfrom among the group consisting of epoxy resin, modified epoxy resin,silicone resin, modified silicone resin, acrylate resin and urethaneresin among the thermosetting resins, and epoxy resin, modified epoxyresin, silicone resin and modified silicone resin are particularlypreferable. For example, it is possible to use a solid epoxy resincomposition prepared by adding 0.5 parts by weight of DBU(1,8-diazabicyclo(5,4,0)undecene-7) (Chemical Formula 6) as a curingaccelerator, 1 part by weight of ethylene glycol (Chemical Formula 7) asa promoter, 10 parts by weight of a titanium oxide pigment and 50 partsby weight of a glass fiber to 100 parts by weight of a colorlesstransparent mixture, which is prepared by dissolving and mixing an epoxyresin comprising triglycidyl isocyanurate (Chemical Formula 1),hydrogenated bisphenol A diglycidyl ether (Chemical Formula 2) and thelike and an acid anhydride comprising hexahydrophthalic anhydride(Chemical Formula 3), 3-methylhexahydrophthalic anhydride (ChemicalFormula 4), 4-methylhexahydrophthalic anhydride (Chemical Formula 5) andthe like so that the acid anhydride is equivalent to the epoxy resin,and partially curing the mixture with heating, thereby B-staging themixture.

The first resin molding 40 is required to serve as a package, and istherefore preferably made of a hard material. Although the first resinmolding 40 may or may not be translucent, it can be designed inaccordance to the application. For example, a light blocking materialmay be mixed in the first resin molding 40 so as to reduce the lightwhich transmits the first resin molding 40. A filler or a diffusingagent may also be mixed so that light emitted by the surface mountedlight emitting apparatus emerges uniformly in the forward and sidewaysdirections. A whitish pigment, rather than dark pigment, may also beadded so as to reduce the absorption of light. In this way, the firstresin molding 40 may contain at least one kind selected from among thegroup consisting of filler, diffusing agent, pigment, fluorescentmaterial, reflective material and light blocking material mixed therein,so as to provide a desired function.

<First Lead, Second Lead>

The first lead 20 has the first inner lead 20 a and the first outer lead20 b. The bottom surface 40 a of the recess 40 c of the first resinmolding 40 in the first inner lead 20 a is exposed, and the lightemitting device 10 is mounted on the exposed portion. While the surfacearea required of the exposed first inner lead 20 a may be such allows itto mount the light emitting device 10, the surface area is preferablylarger when consideration is given to heat conductivity, electricalconductivity and reflectivity. The first inner lead 20 a is electricallyconnected to the first electrode 11 of the light emitting device 10 viaa wire 60. The first outer lead 20 b is a portion which is exposed fromthe first resin molding 40, other than the portion where the lightemitting device is mounted. The first outer lead 20 b is electricallyconnected to the external electrode and also serves to transfer theheat.

The second lead 30 has the second inner lead 30 a and the second outerlead 30 b. The bottom surface 40 a of the recess 40 c of the first resinmolding 40 in the second inner lead 30 a is exposed. While the surfacearea required of the exposed second inner lead 30 b may be such thatallows it to electrically connect to the second electrode 12 of thelight emitting device 10, the surface area is preferably larger whenconsideration is given to reflectivity. The first outer lead 20 b andthe second outer lead 30 b on the back side are exposed and form asubstantially the same plane. This configuration enables it to improvethe stability of mounting of the surface mounted light emittingapparatus. In order to prevent the first inner lead 20 a and the secondinner lead 30 a from short-circuiting on the back sides thereof whensoldering, coating of a thin insulation member 90 may be provided. Theinsulation member 90 is made of a resin or the like.

The first lead 20 and the second lead 30 may be formed from a goodelectrical conductor such as iron, phosphor bronze, copper alloy or thelike. In order to improve the reflectivity to light emitted by the lightemitting device 10, the surfaces of the first lead 20 and the secondlead 30 may be plated with a metal such as silver, aluminum, copper orgold. In order to improve the reflectivity of the surfaces of the firstlead 20 and the second lead 30, these surfaces are preferably smooth.Heat dissipation may be improved by increasing the surface area of thefirst lead 20 and the second lead 30, which makes it possible toeffectively suppress the temperature of the light emitting device 10from rising, so that relatively large current can flow in the lightemitting device 10. Heat dissipation can also be improved by increasingthe thickness of the first lead 20 and the second lead 30. In this case,since it becomes difficult to bend or otherwise process the first lead20 and the second lead 30, the first lead 20 and the second lead 30 arecut into predetermined sizes. When the thickness of the first lead 20and the second lead 30 is increased, the first lead 20 and the secondlead 30 become less likely to undergo deflection so that the lightemitting device 10 can be easily mounted. When the first lead 20 and thesecond lead 30 are formed in thin plates, in contrast, it becomes easierto process the first lead 20 and the second lead 30 by bending into adesired shape.

The first lead 20 and the second lead 30 are a pair of positive andnegative electrodes. While the number of each of the first lead 20 andthe second lead 30 provided may be one, each may also be provided inplurality. When a plurality of the light emitting devices 10 areprovided on the first lead 20, it is necessary to provide a plurality ofthe second leads 30.

<Second Resin Molding>

The second resin molding 50 is provided in order to protect the lightemitting device 10 from force, dust and moisture coming from theoutside. It also enables it to guide the light emitted by the lightemitting device 10 efficiently to the outside. The second resin molding50 is disposed in the recess 40 c of the first resin molding 40.

The second resin molding 50 is formed from a thermosetting resin. Amongthermosetting resins, at least one kind selected from among the groupconsisting of epoxy resin, modified epoxy resin, silicone resin,modified silicone resin, acrylate resin and urethane resin is preferablyused. Among these resins, epoxy resin, modified epoxy resin, siliconeresin and modified silicone resin are preferably used in particular. Thesecond resin molding 50 is preferably formed from a hard material inorder to protect the light emitting device 10. The second resin molding50 is also preferably formed from a resin which has high heatresistance, high weatherability and high light resistance. The secondresin molding 50 may contain at least one kind selected from among thegroup consisting of filler, diffusing agent, pigment, fluorescentmaterial and reflective material mixed therein so as to provide adesired function. The second resin molding 50 may also contain adiffusing agent. For the diffusing agent, barium titanate, titaniumoxide, aluminum oxide, silicon oxide or the like may be preferably used.An organic or inorganic dye or pigment may also be contained for thepurpose of cutting off undesired wavelengths. The second resin molding50 may also contain a fluorescent material 80 which absorbs lightemitted by the light emitting device 10 and converts the wavelengththereof

(Fluorescent Material)

The fluorescent material may be any one which absorbs light from a lightemitting device 10 to convert into light having a different wavelength.For example, the fluorescent material is preferably at least one kindselected from among nitride-based fluorescent material, oxynitride-basedfluorescent material and sialon-based fluorescent material, which areactivated mainly with lanthanoid elements such as Eu and Ce; alkaliearth halogen apatite fluorescent material, alkali earth metal boricacid halogen fluorescent material and alkali earth metal aluminatefluorescent material, which are activated mainly with lanthanoidelements such as Eu, and transition metal elements such as Mn; rareearth aluminate and rare earth silicate, which are activated mainly withalkali earth silicate, alkali earth sulfide, alkali earth thiogallate,alkali earth silicon nitride, germanate, or lanthanoid elements such asCe; and organic and organic complexes activated mainly with lanthanoidelements such as Eu. Specific examples thereof include, but are notlimited to, the followings.

Examples of the nitride-based fluorescent material activated mainly withlanthanoid elements such as Eu and Ce include M₂Si₅N₈:Eu and CaAlSiN₃:Eu(M represents at least one kind selected from among Sr, Ca, Ba, Mg andZn). The nitride-based fluorescent material further includes MSi₇N₁₀:Eu,M_(1.8)Si₅O_(0.2)N₈:Eu and M_(0.9)Si₇O_(0.1)N₁₀:Eu (M represents atleast one kind selected from among Sr, Ca, Ba, Mg and Zn), in additionto M₂Si₅N₈:Eu.

Examples of the oxynitride-based fluorescent material activated mainlywith lanthanoid elements such as Eu and Ce include NSi₂O₂N₂:Eu (Mrepresents at least one kind selected from among Sr, Ca, Ba, Mg and Zn).

Examples of the sialon-based fluorescent material activated mainly withlanthanoid elements such as Eu and Ce includeM_(p/2)Si_(12−p−q)Al_(p+q)O_(q)N_(16−p):Ce and N—Al—Si—O—N(M representsat least one kind selected from among Sr, Ca, Ba, Mg and Zn, qrepresents 0 to 2.5, and p represents 1.5 to 3).

Examples of the alkali earth halogen apatite fluorescent materialactivated mainly with lanthanoid elements such as Eu, and transitionmetal elements such as Mn include M₅(PO₄)₃X:R (M represents at least onekind selected from among Sr, Ca, Ba, Mg and Zn, X represents at leastone kind selected from among F, Cl, Br and I, and R represents at leastone of Eu, Mn, and Eu and Mn).

Examples of the alkali earth metal boric acid halogen fluorescentmaterial include M₂B₅O₉X:R (M represents at least one kind selected fromamong Sr, Ca, Ba, Mg and Zn, X represents at least one kind selectedfrom among F, Cl, Br and I, and R represents at least one of Eu, Mn, andEu and Mn).

Examples of the alkali earth metal aluminate fluorescent materialinclude SrAl₂O₄:R, Sr₄Al₁₄O₂₅:R, CaAl₂O₄:R, BaMg₂Al₁₆O₂₇:R,BaMg₂Al₁₆O₁₂:R and BaMgAl₁₀O₁₇:R (R represents at least one of Eu, Mn,and Eu and Mn).

Examples of the alkali earth sulfide fluorescent material includeLa₂O₂S:Eu, Y₂O₂S:Eu and Gd₂O₂S:Eu.

Examples of the rare earth aluminate fluorescent material activatedmainly with lanthanoid elements such as Ce include YAG-based fluorescentmaterials represented by the composition formulas Y₃Al₅O₁₂:Ce,(Y_(0.8)Gd_(0.2))₃Al₅O₁₂:Ce, Y₃(Al_(0.8)Ga_(0.2))₅O₁₂:Ce,(Y,Gd)₃(Al,Ga)₅O₁₂. Examples thereof further include Tb₃Al₅O₁₂:Ce andLu₃Al₅O₁₂:Ce in which a portion or all of Y is substituted with Tb, Luor the like.

Examples of the other fluorescent material include ZnS:Eu, Zn₂GeO₄:Mnand Mga₂S₄:Eu (M represents at least one kind selected from Sr, Ca, Ba,Mg and Zn, and X represents at least one kind selected from among F, Cl,Br and I).

If desired, the above fluorescent materials can contain at least onekind selected from among Tb, Cu, Ag, Au, Cr, Nd, Dy, Co, Ni and Ti, inplace of Eu or in addition to Eu.

Fluorescent materials other than those described above may also be usedas long as similar performance and effect can be obtained.

The fluorescent material may be such that is excited by the light fromthe light emitting device 10 and emits yellow, reed, green or bluelight, but may also be one that emits light of intermediate color, suchas yellow, blue green or orange. The surface mounted light emittingapparatus which emits light of various colors can be manufactured byusing these fluorescent materials in various combinations.

For example, blue light emitted by a GaN-based compound semiconductor isirradiated on a fluorescent material having composition of Y₃Al₅O₁₂:Ceor (Y_(0.8)Gd_(0.2))₃Al₅O₁₂:Ce which converts the wavelength of thelight. The surface mounted light emitting apparatus can emit white lightby blending the light emitted by the light emitting device 10 and lightemitted by the fluorescent material 60.

For example, the surface mounted light emitting apparatus which emitswhite light with good color rendering property can be provided by usinga fluorescent material 60 made of CaSi₂O₂N₂:Eu or SrSi₂O₂N₂:Eu whichemits light of color from green to yellow, (Sr, Ca)₅(PO₄)₃Cl:Eu whichemits blue light and (Ca, Sr)₂Si₅N₈:Eu which emits red light. This isbecause the desired white light can be achieved simply by varying theproportions of the first fluorescent material and the second fluorescentmaterial, since light rays of red, blue and green colors which are thethree primary colors are used.

<Other Components>

The surface mounted light emitting apparatus may be provided with azener diode as a protective element. The zener diode made by mounted onthe first lead 20 provided on the bottom surface 40 a of the recess 40 cseparately from the light emitting device 10. The zener diode may alsobe mounted on the first lead 20 provided on the bottom surface 40 a ofthe recess 40 c, with the light emitting device 10 mounted thereon. Thesize may be 300 μm square besides 280 μm square.

The wire 60 electrically connects between the second electrode 12 of thelight emitting device 10 and the second lead 30 and between the firstelectrode 11 of the light emitting device 10 and the first lead 20. Thewire 60 is required to have high ohmic contact with the electrode of thelight emitting device 10, high mechanical connectivity, high electricalconductivity and high heat conductivity. Heat conductivity is preferably0.01 cal/(S)(cm²)(° C./cm) or higher, and more preferably 0.5cal/(S)(cm²)(° C./cm) or higher. A wire is provided between a positionright above the light emitting device 10 and a wire bonding area ofplated wiring pattern, so as to establish electrical continuity.

The surface mounted light emitting apparatus of the present invention isprovided with the constitution described above.

<Mounting of the Surface Mounted Light Emitting Apparatus>

The surface mounted light emitting apparatus mounted in electricalconnection with the external electrode is shown. FIG. 3 is a schematicsectional view showing the state of mounting the surface mounted lightemitting apparatus according to the first embodiment.

A heat sink 110 can be provided via a heat conductive adhesive 100 onthe back surface of the surface mounted light emitting apparatus. Theheat conductive adhesive 100 preferable has heat conductivity higherthan that of the material of the first resin molding 40. The heatconductive adhesive 100 may be formed from epoxy resin, silicone resinor the like which has electrically insulating property. The heat sink110 is preferably made of aluminum, copper, tungsten, gold or the likewhich has high electrical conductivity. In addition, the heat sink 110may be provided in contact only with the first lead 20 via the heatconductive adhesive 100 and eutectic metal containing solder havinghigher heat conductivity may be used as the heat conductive adhesive.Since the back surface of the surface mounted light emitting apparatusis smooth, it can be mounted on the heat sink 110 while maintainingstability. Particularly because the first lead 20 and the heat sink 110are provided so as take the shortest possible path to the light emittingdevice 10, high heat dissipation is achieved.

The first outer lead 20 b of the first lead 20 and the second outer lead30 b of the second lead 30 are electrically connected to externalelectrodes. The first lead 20 and the second lead 30 are thick flatplates, and are therefore electrically connected by interposing betweenthe external electrode and the heat sink 90. Lead-free solder is usedfor electrical connection between the first outer lead 20 b and thesecond outer lead 30 b and the external electrodes. Alternatively,electrical connection can also be established by placing the first outerlead 20 b on the external electrode.

Second Embodiment

The surface mounted light emitting apparatus according to the secondembodiment will now be described. Aspects of the constitution similar tothose of the surface mounted light emitting apparatus according to thefirst embodiment will be omitted. FIG. 4 is a schematic plan viewshowing the surface mounted light emitting apparatus according to thesecond embodiment.

In the surface mounted light emitting apparatus, surfaces of the firstlead 21 and the second lead 31 are roughened so as to increase thecontact area with the first resin molding 40. This makes it possible toprevent the first lead 21 and the second lead 31 from coming off thefirst resin molding 40.

Third Embodiment

The surface mounted light emitting apparatus according to the thirdembodiment will now be described. Aspects of the constitution similar tothose of the surface mounted light emitting apparatus of the firstembodiment will be omitted. FIG. 5 is a schematic sectional view showingthe surface mounted light emitting apparatus according to the thirdembodiment.

The surface mounted light emitting apparatus employs the first lead 22and the second lead 32 which are formed in thin flat plates. Thisconstitution makes it possible to provide the surface mounted lightemitting apparatus of more compact and thin construction. The thin flatplate may be formed in rectangular shape as in the first embodiment, ormay be roughened as in the second embodiment.

Fourth Embodiment

The surface mounted light emitting apparatus according to the fourthembodiment will now be described. Aspects of the constitution similar tothose of the surface mounted light emitting apparatus of the thirdembodiment will be omitted. FIG. 6 is a schematic sectional view showingthe surface mounted light emitting apparatus according to the fourthembodiment.

In the surface mounted light emitting apparatus, the first lead 23 andthe second lead 33 are bent toward the principal surface. The first lead23 and the second lead 33 are formed with small thickness, and thereforecan be easily bent. This enables it for the solder to creep up to thefirst outer lead 23 b and the second outer lead 33 b which are bent whenmounting, thereby firmly securing the members. During the transfermolding process in which the first resin is poured, since the firstinner lead 23 a and the second inner lead 33 b are interposed betweenthe upper die and the lower die, burrs are not formed even when thefirst inner lead 23 a and the second inner lead 33 b are formed withsmall thickness.

Fifth Embodiment

The surface mounted light emitting apparatus according to the fifthembodiment will now be described. Aspects of the constitution similar tothose of the surface mounted light emitting apparatus of the thirdembodiment will be omitted. FIG. 7 is a schematic sectional view showingthe surface mounted light emitting apparatus according to the fifthembodiment. FIG. 8 is a schematic sectional view showing the state ofmounting the surface mounted light emitting apparatus according to thefifth embodiment.

In the surface mounted light emitting apparatus, the first outer lead 24b and the second outer lead 34 b are bent toward the principal surface,and are further bent toward the outside. With this configuration, sincethe surface mounted light emitting apparatus can be interposed betweenthe heat sink 90 and the external electrode, it is made easier to mountthe surface mounted light emitting apparatus and stability of mountingis improved. The positions of connecting the first lead 24 and thesecond lead 34 to the external electrode can be made higher than thepositions of fastening the first lead 24 and the second lead 34 to theheat sink 90. As a result, since the entire surface mounted lightemitting apparatus except for the light emitting surface can beconcealed from the mounting substrate, the mounting substrate can beefficiently used as a reflector.

Sixth Embodiment

The surface mounted light emitting apparatus according to the sixthembodiment will now be described. Aspects of the constitution similar tothose of the surface mounted light emitting apparatus of the thirdembodiment will be omitted. FIG. 9 is a schematic sectional view showingthe surface mounted light emitting apparatus according to the sixthembodiment.

The surface mounted light emitting apparatus has the heat sink 91incorporated in the first resin molding 41. The heat sink 91 is disposedon the back surface of the first inner lead 25 a. This configurationenables it to provide the surface mounted light emitting apparatus whichhas the heat sink 91 integrated therein. It also eliminates thenecessity of separately attaching the heat sink 91 and the necessity toconsider the bonding between the surface mounted light emittingapparatus and the heat sink 91. By disposing the heat sink 91 so as tobe substantially flush with the back surface of the resin molding 41,stabilization of the surface mounted light emitting apparatus isimproved. The first outer lead 25 b and the second outer lead 35 b arebent in a predetermined shape.

In this surface mounted light emitting apparatus, the first inner lead25 a and the second inner lead 35 a are interposed between the upper dieand the lower die, and predetermined recesses are provided on theprincipal surface side and the back side of the first inner lead 25 aand the second inner lead 35 a. This constitution enables it to moreeffectively prevent the first inner lead 25 a and the second inner lead35 a from coming off. It is also enabled to provide the surface mountedlight emitting apparatus having predetermined thickness.

<Method for Manufacturing Surface Mounted Light Emitting Apparatus>

The method of manufacturing the surface mounted light emitting apparatusof the present invention will now be described. This manufacturingmethod is related to the surface mounted light emitting apparatusdescribed above. FIGS. 10(a) through 10(e) are schematic sectional viewsshowing the processes of manufacturing the surface mounted lightemitting apparatus of the first embodiment.

The first inner lead 20 a and the second inner lead 30 a correspondingto the bottom surface 40 a of the recess 40 c of the first resin molding40 and the first outer lead 20 b and the second outer lead 30 b areinterposed between the upper die 120 and the lower die 121 (firstprocess).

The upper die 120 has a recess corresponding to the recess of the firstresin molding. The portion of the upper die 120 which corresponds to thebottom surface 40 a of the recess 40 c of the first resin molding 40 isformed so as to bring the first inner lead 20 a and the second innerlead 30 a into contact with each other.

The first thermosetting resin is poured into the recess interposedbetween the upper die 120 and the lower die 121 by the transfer moldingprocess (second process).

In the transfer molding process, the first thermosetting resin in theform of pellets having predetermined size is put into a predeterminedcontainer. A pressure is applied to the container. The firstthermosetting resin in molten state is poured into the recess interposedbetween the upper die 120 and the lower die 121 which communicates withthe container. Then the upper die 120 and the lower die 121 are heatedto a predetermined temperature, so as to cure the first thermosettingresin that has been poured therein. The series of these operations iscalled the transfer molding process.

Since the first inner lead 20 a and the second inner lead 30 a areinterposed between the upper die and the lower die, the first inner lead20 a and the second inner lead 30 a can be suppressed from flutteringduring the transfer molding process, so that the resin molding withoutburrs can be made.

As the first thermosetting resin which has been poured is heated tocure, the first resin molding 40 is formed (third process).

Thus the first resin molding 40 is formed from the thermosetting resin.This provides a package which has high heat resistance, high lightresistance and high bonding strength. And the first resin molding 40formed from the thermosetting resin having the recess 40 c comprisingthe bottom surface 40 a and the side surface 40 b is provided.

Then the upper die 120 and the lower die 121 are removed (fourthprocess).

The upper die 120 and the lower die 121 are removed in order to mountthe light emitting device 10. When the resin has not been cured enough,additional curing treatment is applied so as to increase the mechanicalstrength of the resin molding 40 to a level that allows the subsequentoperations.

The light emitting device 10 is mounted on the first inner lead 20 a.The first electrode 11 of the light emitting device 10 and the firstinner lead 20 a are electrically connected with each other. The secondelectrode 12 of the light emitting device 10 and the second inner lead20 b are electrically connected with each other (fifth process).

The first electrode 11 and the first inner lead 20 a are electricallyconnected via the wire 60. In case the light emitting device 10 haselectrodes on the top surface and the bottom surface thereof, however,the electrical connection is made by die bonding only, instead of usingthe wire. Then the second electrode 12 and the second inner lead 30 aare electrically connected via the wire 60.

The second thermosetting resin is placed in the recess 40 c wherein thelight emitting device 10 is mounted (sixth process).

While the second thermosetting resin may be placed by dripping,injection, extrusion or other methods, dripping is preferably employed.Dripping enables it to effectively purge air which remains in the recess40 c. The second thermosetting resin preferably contains the fluorescentmaterial 80 mixed therein, which makes it easy to control the color toneof light emitted by the surface mounted light emitting apparatus.

As the second thermosetting resin is heated to cure, the second resinmolding is formed (seventh process).

Thus the surface mounted light emitting apparatus can be made easily. Asthe first resin molding 40 and the second resin molding 50 are formedfrom thermosetting resins, the surface mounted light emitting apparatushaving high bonding property can be provided. There occurs no peel-offin the interface between the first resin molding 40 and the second resinmolding 50, and the surface mounted light emitting apparatus which hashigh heat resistance, high light resistance and high bonding strength isprovided.

Example 1

The surface mounted light emitting apparatus of Example 1 is shown inFIG. 1 and FIG. 2. Aspects of the constitution similar to those of thesurface mounted light emitting apparatus of the first embodiment will beomitted.

The surface mounted light emitting apparatus of Example 1 comprises thelight emitting device 10, the first resin molding 40 on which the lightemitting device 10 is placed and the second resin molding 50 whichcovers the light emitting device 10. The first resin molding 40 moldsintegrally the first lead 20 whereon the light emitting device 10 ismounted and the second lead 30 which is electrically connected to thelight emitting device 10. The first resin molding 40 has the recess 40 cwhich has the bottom surface 40 a and the side surface 40 b, while theopening of the recess 40 c is made wider than the bottom surface 40 a,and the side surface 40 b is inclined.

The light emitting device 10 is made of GaN semiconductor which emitsblue light. The light emitting device 10 has the first electrode 11 andthe second electrode 12 provided on the same surface, and is bonded ontothe first lead 20 in face-up position by using a die bonding resin(epoxy resin containing silver mixed therein). The first electrode 11 iselectrically connected to the first lead 20 via the gold wire 60. Thesecond electrode 12 is also electrically connected to the second lead 30via the gold wire 60. The first lead 20 and the second lead 30 are madeof copper, and the portions thereof exposed from the first resin molding40 are plated with silver. The first lead 20 and the second lead 30 aremade of relatively thick (about 0.5 mm) sheets, and back sides of thefirst lead 20 and the second lead 30 are exposed. The first resinmolding 40 is formed by mixing 100 parts by weight of a mixture inequivalent weight proportions of an epoxy resin consisting oftriglycidyl isocyanurate and an acid anhydride consisting ofhexahydrophthalic anhydride, 0.5 parts by weight of DBU, 1 part byweight of ethylene glycol, 10 parts by weight of a titanium oxidepigment and 50 parts by weight of a glass fiber. The second resinmolding 50 is formed from a silicone resin. The second resin molding 50contains the YAG fluorescent material 80 having the composition of(Y_(0.8)Gd_(0.2))₃Al₅O₁₂:Ce mixed uniformly therein. The second resinmolding 50 is placed in the recess 40 c which has the bottom surface 40a and the side face 40 b, and the surface of the second resin molding 50is made flush with the top surface of the recess 40 c. With thisconstitution, quantity of the fluorescent material 80 is controlledconstant among products. The insulating member 90 comprising an epoxyresin sheet of predetermined thickness is adhered onto the back sides ofthe first lead 20 and the second lead 30.

The surface mounted light emitting apparatus of the Example 1 ismanufactured by the processes described below. FIG. 10 is schematicsectional view showing the processes of manufacturing the surfacemounted light emitting apparatus of Example 1.

Predetermined lead frame is punched through, and plurality of the firstleads 20 and the second leads 30 are provided. The lead frame is securedonto the lower die 121 which is heated to about 150° C. The upper die120 which is similarly heated to about 150° C. is placed so as tointerpose the lead frame. Portions which are interposed are thosecorresponding to the inner leads 20 a, 30 a and the outer leads 20 b, 30b of the first lead 20 and the second lead 30. Tablets obtained bypunching the epoxy resin compound corresponding to the first resinmolding 40 are placed in a die cylinder. The tablets are poured into thedie by means of a piston (transfer molding process). The epoxy resinwhich has been poured is heated to about 150° C. for about 3 minutes inthe die for preliminary curing. Then the upper die 120 and the lower die121 are separated and the semi-cured epoxy resin compound is taken outof the dies. The resin molding is again heated to about 150° C. forabout 3 hours so as to fully cure. Thus the lead frame which molds thefirst resin molding 40 with the fully cured epoxy resin compoundintegrally formed with the lead frame is obtained. The first resinmolding 40 has the recess 40 c which has the bottom surface 40 a and theside surface 40 b, and the lead frame is exposed on the bottom surface40 a. Portions of the lead frame corresponding to the outer leads 20 b,30 b are plated.

Then the light emitting device 10 is die-bonded onto the bottom surface40 a of the recess 40 c. The first electrode 11 of the light emittingdevice 10 and the first inner lead 20 a of the first lead 20, and thesecond electrode 12 of the light emitting device 10 and the second innerlead 30 a of the second lead 30 are electrically connected with eachother via the wires 60.

Then the silicone resin corresponding to the second resin molding 50which contains the YAG fluorescent material 80 mixed uniformly thereinis dripped into the recess 40 c up to the top surface thereof. The YAGfluorescent material 80 settles according to factors such as theviscosity of the silicone resin. As the YAG fluorescent material 80settles, the YAG fluorescent material 80 can be disposed around thelight emitting device 10, thereby providing the surface mounted lightemitting apparatus having the desired color tone of light emission.After the silicone resin has been dripped, it is cured to obtain thesecond resin molding 50.

Last, the lead frame is cut off at predetermined positions, so as toform the first outer lead 20 b and the second outer lead 30 b. Thiscompletes the surface mounted light emitting apparatus of Example 1.

The surface mounted light emitting apparatus of the present inventioncan be used in illumination apparatus, display, backlight for mobilephone, flash light of camera, auxiliary light source for illuminationand the like.

While preferred embodiments of the invention have been described andillustrated above, it should be understood that these are exemplary ofthe invention and are not to be considered as limiting. Additions,omissions, substitutions, and other modifications can be made withoutdeparting from the spirit or scope of the present invention.Accordingly, the invention is not to be considered as limited by theforegoing description but is only limited by the scope of the appendedclaims.

What is claimed is:
 1. A surface mounted light emitting apparatuscomprising: a light emitting device, a first resin molding whichintegrally molds a first lead whereon the light emitting device ismounted and a second lead which is electrically connected to the lightemitting device, and a second resin which covers the light emittingdevice, wherein the first resin molding has a single recess forreceiving said light emitting device, said recess comprising, in across-sectional view, a single bottom surface and a single side surfaceat each side of the recess made from the first resin molding, a frontface of the first lead and a front face of the second lead being exposedfrom the first resin molding at the single bottom surface of the recess,with the light emitting device being mounted on the exposed portion ofthe first lead; and the first resin molding and the second resin areformed from thermosetting resins, and the first resin molding includesat least one kind selected form the group consisting of filler,diffusing agent, pigment, fluorescent material, reflective material andlight blocking material; wherein said first resin molding is disposedcontinuously from said single side surface of the recess to between thefirst lead and the second lead; wherein a surface of the first lead isroughened so as to increase a contact area with the first resin molding,wherein each of the first lead and the second lead has at least one backside that is opposite to the bottom surface of the recess and is exposedfrom the first resin molding; wherein both of said first lead and saidsecond lead have a plate-like shape with a substantially constantthickness, and the thickness of said first lead and the thickness of thesecond lead are substantially the same; and wherein at least a part ofthe at least one back side of the first lead, and at least a part of theat least one back side of the second lead, and at least a part of a backside of the first resin lie on substantially the same plane to form acontinuous flat plane.
 2. The surface mounted light emitting apparatusaccording to claim 1, wherein the light emitting device emits lighthaving a wavelength in a range from 400 nm to 530 nm.
 3. The surfacemounted light emitting apparatus according to claim 1, wherein the firstresin molding comprises at least one kind selected from the groupconsisting of titanium oxide, silica and alumina.
 4. The surface mountedlight emitting apparatus according to claim 1, wherein the first leadand the second lead comprise at least one selected from the groupconsisting of iron, phosphor bronze, or copper alloy.
 5. The surfacemounted light emitting apparatus according to claim 1, wherein the firstresin molding is formed from at least one kind selected from the groupconsisting of epoxy resin, modified epoxy resin, silicone resin,modified silicone resin, acrylate resin and urethane resin.
 6. Thesurface mounted light emitting apparatus according to claim 1, whereinthe second resin molding is formed from at least one kind selected fromthe group consisting of epoxy resin, modified epoxy resin, siliconeresin, modified silicone resin, acrylate resin and urethane resin. 7.The surface mounted light emitting apparatus according to claim 1,wherein the second resin molding includes at least one kind selectedfrom the group consisting of filler, diffusing agent, pigment,fluorescent material and reflective material.
 8. The surface mountedlight emitting apparatus according to claim 1, wherein said first resinmolding disposed between the first lead and the second lead separatesthe first lead from the second lead below the recess.
 9. The surfacemounted light emitting apparatus according to claim 1, wherein the frontface of the first lead, the front face of the second lead and a frontface of the first resin molding disposed between the first lead and thesecond lead are on the same plane at the single bottom surface of saidrecess.
 10. The surface mounted light emitting apparatus according toclaim 1, wherein the single bottom surface of said recess is flat. 11.The surface mounted light emitting apparatus according to claim 1,wherein said single side surface continuously maintains a substantiallyconstant inclination from a top of said recess to said single bottomsurface and an inclination angle between said single side surface andsaid single bottom surface of said recess is 95 to 150 degree.
 12. Thesurface mounted light emitting apparatus according to claim 1, wherein asurface of said second lead are roughened so as to increase a contactarea with the first resin molding.
 13. The surface mounted lightemitting apparatus according to claim 1, wherein the first lead and thesecond lead are plated with at least one selected from the groupconsisting of silver, aluminum, copper and gold.
 14. The surface mountedlight emitting apparatus according to claim 7, wherein the second resincomprises a fluorescent material that is excited by light from the lightemitting device and emits light having a spectrum in at least one ofred, orange, yellow, green, blue green and blue region.
 15. The surfacemounted light emitting apparatus according to claim 1, wherein a recessis formed on a side surface of said first lead or said second lead. 16.A surface mounted light emitting apparatus comprising: a light emittingdevice, a first resin molding which integrally molds a first leadwhereon the light emitting device is mounted and a second lead which iselectrically connected to the light emitting device, and a second resinwhich covers the light emitting device, wherein the first resin moldinghas a single recess for receiving said light emitting device, saidrecess comprising, in a cross-sectional view, a single bottom surfaceand a single side surface at each side of the recess made from the firstresin molding, a front face of the first lead and a front face of thesecond lead being exposed from the first resin molding at the singlebottom surface of the recess, with the light emitting device beingmounted on the exposed portion of the first lead; and the first resinmolding and the second resin are formed from thermosetting resins, andthe first resin molding includes at least one kind selected form thegroup consisting of filler diffusing agent, pigment, fluorescentmaterial, reflective material and light blocking material; wherein saidfirst resin molding is disposed continuously from said single sidesurface of the recess to between the first lead and the second lead;wherein a surface of the first lead is roughened in a plan view, whereineach of the first lead and the second lead has at least one back sidethat is opposite to the bottom surface of the recess and is exposed fromthe first resin molding; wherein both of said first lead and said secondlead have a plate-like shape with a substantially constant thickness,and the thickness of said first lead and the thickness of the secondlead are substantially the same; and wherein at least a part of the atleast one back side of the first lead, and at least a part of the atleast one back side of the second lead, and at least a part of a backside of the first resin lie on substantially the same plane to form acontinuous flat plane.